The present invention relates to a method and an apparatus for automatically feeding metal profiles in bar form, particularly iron rods for reinforced concrete, in systems for machining said profiles.
It is known that the rods used for example to manufacture reinforcement frames for reinforced concrete can be obtained starting from iron rods in bar form. For this purpose, the bars are fed, individually or in groups, to machines that automatically machine them into a series of selected products.
In particular, systems are known which automatically cut, store and transfer the bars to such machines. These systems have a magazine, also known as stock magazine, which is laterally adjacent to a conveyance line, along which the measurement elements and the cutter that cuts the bars are arranged; downstream of the cutting elements, the line has means for transferring the bars to suitable storage compartments. Conveyor means are associated with the storage compartments and transfer the bars cut to size to a bending machine or to a line for the exit of the straight bars.
Currently, the bars are taken from the stock magazine and fed to the conveyance line manually by one or more operators. The operators untangle the individual bars taken from the bundle deposited in the stock magazine, for example by gripping them at their opposite ends, and after untangling them from the remainder of the bundle they allow them to fall transversely onto the conveyance line, which is capable of transferring all the selected bars simultaneously, because said bars rest on a series of motorized rollers.
The bar feeding operation is particularly awkward for the operators, who are forced to work in a very noisy and potentially dangerous environment. Clearly, the discomfort is increased by the fact that the bars to be picked up are generally long and are therefore heavy and difficult to handle.
It should also be noted that during said feeding step it is also necessary to determine the correct number of bars to be fed to the machine according to the machining requirements. For example, the number of bars to be fed to the cutting elements of the machine is determined, in relation to the machining capacity of said elements, by the diameter of said bars, by the characteristics of the material being machined and by production requirements.
U.S. Ser. No. 10/353,985, by the same Applicant, discloses a method for automatically feeding metal profiles to machines, such as in particular benches for cutting said profiles. The method entails gripping a set of said profiles by means of suitable grip means and depositing them onto a screw feeder device, which transfers a counted number of said profiles to the receiving elements of the machine. Said device is suitable to feed machines that have a traction head which, once it has gripped one end of the bars being machined, is capable of extracting the bars from the bundle to which they belong, but finds no application in machines of a different type, known as xe2x80x9ccutting linesxe2x80x9d, i.e., machines that do not have a traction system capable of performing the longitudinal extraction of the bars from the bundle into which they have been packaged by the manufacturer.
The aim of the present invention is to solve the above cited problem by providing a method that allows to separate the correct number of metal profiles in bar form from the bundle to which they belong in order to automatically feed said bars to systems for machining said bars that lack traction means capable of performing the longitudinal extraction of the bars from the bundle but have instead a bar conveyor that is usually constituted by motorized rollers on which the bars are rested after they have been untangled from the bundle to which they belong.
Within this aim, an object of the present invention is to provide a method and an apparatus that allow to determine the correct number of profiles to be picked up and fed to the machine according to production requirements.
Another object of the invention is to provide an apparatus that allows to provide said method by means of a structure that is simple in concept, assuredly reliable in operation, versatile in use, low in cost and is applicable even to existing machines.
This aim and these and other objects are achieved, according to the present invention, by the method for automatically feeding metal profiles in bar form in systems for machining said profiles, characterized in that it comprises the steps of:
(a). gripping a set of metal profiles (2) in bar form in one or more sections, from a magazine (5) that collects said profiles (2);
(b). transferring said set of metal profiles (2) in bar form or the gripped portion of said set of metal profiles (2) in bar form into a raised position;
(c). arranging said metal profiles (2) in bar form or the gripped portion of said set of metal profiles (2) in bar form on a transfer device (10) provided with means (16) for separating said metal profiles (2);
(d). counting a preset number of said metal profiles to be fed at each work cycle;
(e). unloading the excess metal profiles into the same magazine from which they originated;
(f). untangling the metal profiles taken previously from the bundle to which they belong and counted, engaging said preset metal profiles to be fed by means of auxiliary supporting means coupled to said transfer device and actuated gradually along the longitudinal axis of said metal profiles;
(g). transferring and unloading the profiles thus selected onto a conveyance and measurement line in order to feed a machine arranged downstream.